There presently exists thermal binding products that include wraparound covers with adhesive in the spine. These covers may be made of a one or two piece wrap around paper, or paper/plastic combination. They have also been made by utilizing a stiff channel which can be metal in combination with paper or plastic covers that can be of a permanent or temporary nature. These products may be comprised of U-shaped channels of metal with an adhesive placed either directly onto the metal or placed on an absorbent material that has been attached to the metal. The problem of guiding pages that are inserted into such folders to avoid sheets being caught by a protruding lip has been addressed in the prior art with the use of end sheet liners, or the shaped application of an internal adhesive.
Desktop thermal binding machines and thermal binding covers have been developed and gained some acceptance in document binding over the past 30 years or so. The basic product is an empty soft cover or hard cover book that has a hot melt adhesive or resin in the spine. One picks a cover with the appropriate spine width and places the sheets to be bound inside. The cover is then placed spine down against a heated plate. After a minute or so the adhesive liquefies to a point where it can slightly wick into the sheets. The cover is removed, and placed in a rack to cool down, after which time one has a bound book. This bond is permanent and cannot be undone without tearing a page unless the cover is reinserted into a binding machine, reheated and carefully edited. This makes the report more suitable for legal documents and similar presentations where alterations would not be welcome.
The various thermal binding machines that form the bulk of the market operate in a temperature range from 250 F to over 375 F. The machines are basically hotplates with vertical holders and timers. Because high temperatures are involved, it is necessary to have at least one or both covers attached to the U-shaped spine or a complete wrap-around cover in order to place and remove the booklet from the binding machine. A disadvantage of this arrangement is that covers that already have hot melt adhesive inside cannot be run through printers for desktop customization and any other customization, like foil-stamping, requires additional handling. One solution to this problem has been to use a permanent glue to pre-attach temporary front and back covers to a U-shaped metal channel. A customized front and back cover can then be inserted and the temporary covers can be torn off after the binding process has been completed. Such covers require a wide variety of predetermined spine widths to accommodate the varying range of sheets to be bound. Also, this process is quite time consuming.
Accordingly, another object of the present invention is to provide a product and system that eliminate the need for temporary front and back covers.
Still another object of the present invention is to provide a product and system having permanent front and back covers can be readily printed or customized in standard formats. The following represent an additional list of objects of the present invention:
(a) a new and simpler element for producing an effective binding;
(b) a binding that is in the form of an extrusion or co-extrusion used to create the binding element;
(c) an improved binding element that can be readily attached to sheets of paper and front and back covers for easy insertion into and removal from a thermal binding machine;
(d) an improved binding element and an associated method of using the binding element and in which there is eliminated the requirement for handles or attached cover sheets;
(e) a means to allow the binding elements to have a greater range of content or sheet number thus requiring fewer spines sizes to be inventoried;
(f) a means for manufacturing of the binding element itself with extrusion or co-extrusion techniques.